Vemurafenib (PLX4032) structure, NCBI image

This morning the FDA announced approval of Zelboraf (vemurafenib) for treatment of some patients advanced melanoma. This is the second drug the agency has approved for this disease in recent months, after nearly two decades of a lack of new or effective therapies for melanoma.

Zelboraf is a pill. This small-molecule drug is thought to work by inhibiting an enzyme in malignant melanoma cells that have a specific BRAF mutation. A few months ago I wrote on this promising new drug, which goes by other names including PLX-0432.

The FDA also approved a companion test, cobas 4800 BRAF V600 Mutation Test, to check for the relevant mutation in patients’ tumors. Both the drug and the test are manufactured by Roche.

The other recently-approved melanoma drug, Yervoy (ipilimumab) is an antibody that’s given by intravenous infusion. This immune modulator, manufactured by Bristol-Meyers Squibb, works by a completely different mechanism: it blocks an immune system inhibitor, CTLA-4, and so “revs up” the body’s healthy immune cells in their capacity to destroy malignant melanoma cells.

Both new drugs are costly. A clinical trial, to test how the two drugs might work together in patients with the relevant BRAF mutation, should open for enrollment in September.

H/T to Sally Church @maverickny‘s early post on Pharma Strategy Blog.

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